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            <small>
              <a href="#Procedure">Procedure<br></a>
              <a href="#Abstract">Abstract<br></a>
              <a href="#Required_Reading">Required_Reading<br></a>
              <a href="#Keywords">Keywords<br></a>
              <a href="#Brief_I/O">Brief_I/O<br></a>
              <a href="#Detailed_Input">Detailed_Input<br></a>

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              <small>               <a href="#Detailed_Output">Detailed_Output<br></a>
              <a href="#Parameters">Parameters<br></a>
              <a href="#Exceptions">Exceptions<br></a>
              <a href="#Files">Files<br></a>
              <a href="#Particulars">Particulars<br></a>
              <a href="#Examples">Examples<br></a>

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              <small>               <a href="#Restrictions">Restrictions<br></a>
              <a href="#Literature_References">Literature_References<br></a>
              <a href="#Author_and_Institution">Author_and_Institution<br></a>
              <a href="#Version">Version<br></a>
              <a href="#Index_Entries">Index_Entries<br></a>
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<h4><a name="Procedure">Procedure</a></h4>
<PRE>
   void radrec_c ( SpiceDouble range, 
                   SpiceDouble ra, 
                   SpiceDouble dec, 
                   SpiceDouble rectan[3] ) 
</PRE>
<h4><a name="Abstract">Abstract</a></h4>
<PRE>
 
   Convert from range, right ascension, and declination to rectangular
   coordinates.
 </PRE>
<h4><a name="Required_Reading">Required_Reading</a></h4>
<PRE>
 
   None. 
 </PRE>
<h4><a name="Keywords">Keywords</a></h4>
<PRE>
 
   CONVERSION,   COORDINATES 
 

</PRE>
<h4><a name="Brief_I/O">Brief_I/O</a></h4>
<PRE>
 
   VARIABLE  I/O  DESCRIPTION 
   --------  ---  --------------------------------------------------- 
   range      I   Distance of a point from the origin. 
   ra         I   Right ascension of point in radians. 
   dec        I   Declination of point in radians. 
   rectan     O   Rectangular coordinates of the point.
 </PRE>
<h4><a name="Detailed_Input">Detailed_Input</a></h4>
<PRE>
 
   range      is the distance of the point from the origin.  Output
              units are the same as the units associated with `range.'
 
   ra         is the right ascension of the input point:  the angular
              distance measured toward the east from the prime meridian
              to the meridian containing the input point. The direction
              of increasing right ascension is from the +X axis towards
              the +Y axis.

              The range (i.e., the set of allowed values) of 
              `ra' is unrestricted.  Units are radians.

   dec        is the declination of the point.  This is the angular 
              distance from the XY plane to the point.  

              The range of `dec' is unrestricted.  Units are radians.
 </PRE>
<h4><a name="Detailed_Output">Detailed_Output</a></h4>
<PRE>
 
   rectan     is the array containing the rectangular coordinates of 
              the point.  The output units associated with `rectan'
              are those associated with the input `range.'
</PRE>
<h4><a name="Parameters">Parameters</a></h4>
<PRE>
 
   None. 
 </PRE>
<h4><a name="Exceptions">Exceptions</a></h4>
<PRE>
 
   Error free. 
 </PRE>
<h4><a name="Files">Files</a></h4>
<PRE>
 
   None. 
 </PRE>
<h4><a name="Particulars">Particulars</a></h4>
<PRE>
   None.
 </PRE>
<h4><a name="Examples">Examples</a></h4>
<PRE>
 
   The following code fragment converts right ascension and 
   declination from the B1950 reference frame to the J2000 frame.
 
      #include &quot;SpiceUsr.h&quot;

      SpiceDouble      ra;
      SpiceDouble      dec; 
      SpiceDouble      r;
      SpiceDouble      rotab  [ 3 ][ 3 ]; 
      SpiceDouble      oldvec [ 3 ];
      SpiceDouble      newvec [ 3 ];


      <b>radrec_c</b> ( 1.0, ra, dec, oldvec );

      <a href="pxform_c.html">pxform_c</a> ( &quot;B1950&quot;, &quot;J2000&quot;, 0.0, rotab );

      <a href="mxv_c.html">mxv_c</a>    ( rotab,   oldvec, newvec );
      <a href="recrad_c.html">recrad_c</a> ( newvec,  &amp;r,     &amp;ra,    &amp;dec ); 
 
 </PRE>
<h4><a name="Restrictions">Restrictions</a></h4>
<PRE>
 
   None. 
 </PRE>
<h4><a name="Literature_References">Literature_References</a></h4>
<PRE>
 
   &quot;Celestial Mechanics, A Computational Guide for the Practitioner&quot; 
   by Laurence G. Taff 
 </PRE>
<h4><a name="Author_and_Institution">Author_and_Institution</a></h4>
<PRE>
 
   N.J. Bachman    (JPL)
   H.A. Neilan     (JPL) 
   E.D. Wright     (JPL)
 </PRE>
<h4><a name="Version">Version</a></h4>
<PRE>
 
   -CSPICE Version 1.0.2, 28-JUL-2003 (NJB) 
   
      Various header corrections were made.

   -CSPICE Version 1.0.1, 13-APR-2000 (NJB) 
   
      Made some minor updates and corrections in the code example.
      
   -CSPICE Version 1.0.0, 08-FEB-1998 (EDW)
</PRE>
<h4><a name="Index_Entries">Index_Entries</a></h4>
<PRE>
 
   range ra and dec to rectangular coordinates 
   right_ascension and declination to rectangular 
 </PRE>
<h4>Link to routine radrec_c source file <a href='../../../src/cspice/radrec_c.c'>radrec_c.c</a> </h4>

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   <pre>Wed Jun  9 13:05:28 2010</pre>

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